That gives you nut retention, but doesn't ensure your nut stays tight. If the nut is under any serious load, having it back off will cause damage, possibly stud breaking damage.

Attached Linked to is a presentation about another type of washer showing just how good NordLock are. I found this after Hentai linked a product that included Heico-Lock washers, identical to NordLock, but cheaper.

Original: http://www.schnorr.com/downloads/techni ... /file.html
Cached: http://stuff.fredcooke.com/NordLockVers ... shers.pptx

This is the other type that appears better than the NordLock wedge type: http://schnorr.com/products/safety-washers.html

Fred.

Yamaha likes splined fold-over washers on the drive sprocket and clutch hubs, with high tightening torques and loads. Of course, you're talking a 20-25mm splined shaft with a thread for the retaining nut, not a 6mm bolt.